Function parseExpression

src/sys/options.cxx:348–364

Use FieldFactory to evaluate expression

namespace {
/// Use FieldFactory to evaluate expression
double parseExpression(const Options::ValueType& value, const Options* options,
                       const std::string& type, const std::string& full_name) {
  try {
    // Parse the string, giving this Option pointer for the context
    // then generate a value at t,x,y,z = 0,0,0,0
    auto gen = FieldFactory::get()->parse(bout::utils::get<std::string>(value), options);
    if (!gen) {
      throw ParseException("FieldFactory did not return a generator for '{}'",
                           bout::utils::variantToString(value));
    }
    return gen->generate({});
  } catch (ParseException& error) {
    // Convert any exceptions to something a bit more useful
    throw BoutException(_("Couldn't get {} from option {:s} = '{:s}': {}"), type,
                        full_name, bout::utils::variantToString(value), error.what());
  }
}

/// Helper function to print `key = value` with optional source
template <class T>